In an embodiment, a runtime callback function is a part of a code that is invoked upon execution of an associated function. To execute the runtime callback function associated with an in-memory computing engine, multidimensional analytical metadata associated with an application server is received and transformed into an in-memory executable metadata, to generate an instance of an in-memory executable calculation scenario. The instance of the in-memory executable calculation scenario is analyzed to determine process callbacks associated with nodes of the in-memory executable calculation scenario. Based upon the determined process callbacks, the runtime callback function is executed by executing a selection callback at the nodes and a transformation callback at part providers associated with the in-memory executable calculation scenario.